Boat fender strap



FIG. 1 is an upper front perspective view showing my new design for a boat fender strap, wherein the broken line showing of a boat surface, a suction cup, and a fender is for illustrative purposes only and forms no part of my claimed design; and,

FIG. 2 is an upper rear perspective view thereof. 

The ornamental design for a boat fender strap, as shown and described. 